This week, Congressman Raúl Grijalva and the Center for Biological Diversity filed a lawsuit in the US district court of Arizona against Trump’s border wall project. The suit asks that the government undertake an environmental impact analysis before they can begin construction of the wall.

“American environmental laws are some of the oldest and strongest in the world, and they should apply to the borderlands just as they do everywhere else,” Grijalva said in a statement. “Trump’s wall — and his fanatical approach to our southern border — will do little more than perpetuate human suffering while irrevocably damaging our public lands and the wildlife that depend on them.”

The lawsuit hinges on the National Environmental Policy Act, which puts large federal programs (such as this border wall) under review of their environmental impact. The worry, according to experts, is that the wall’s impact on public lands and wildlife could be enormous. A comprehensive review would take several years to complete.

“When you have such beautiful wilderness areas as we have here in Arizona, the idea of putting this large wall that prevents the migration of animals, that scars the earth itself, and especially knowing how ineffectual it is, is something that is just sad,” Juanita Molina, the executive director of Border Action Network, told NPR in February.

The government is already in the bidding process for the wall’s construction, soliciting several companies to complete the project. But Congress has not agreed on funding the wall, and that in itself is a large issue for its construction. That, accompanied by this new lawsuit, has environmental activists optimistic.

“This lawsuit is great news for wildlife, cultures, communities, and rivers along the United States–Mexico border,” says Jen Pelz, the Wild Rivers program director at Wild Earth Guardians. “The beauty of this region is the diversity of its people and its ecosystems. Trump’s wall, like his other misguided policies, seeks to divide and destroy the region for his own political gain. An environmental analysis of the project is critically important to assess the many harmful environmental, as well as social and economic, impacts of a wall.”